Video cameras capturing motion video imagery are commonly used in monitoring systems, surveillance system, access control system, etc.
Many settings of such a camera are relying on parameters of the environment in which the camera is mounted. Mapping surveillance cameras and/or monitoring cameras onto a map showing a surveyed/monitored area is therefore very useful for many applications. For example the map may be used to locate specific cameras for repair or simply to locate where a particular incident being captured on video really occurred. Moreover, the camera on the map may be paired with video streams originating from the specific camera in order to facilitate selection of a video stream related to the area in the map. The position data of the camera may also be recorded in the video in order to enable identification of where the video was captured.
This type of mapping may of course be performed manually by having a person checking where all the cameras are positioned and enter them onto a paper map or a digital map. The geographic positioning within the digital map may be performed by simply selecting a position in a map showed on a display or by entering coordinates representing the position of the camera. These coordinates may be given in any geographic coordinate system as long as the position is uniquely identified. The geographic position may also or alternatively be inserted into the video stream, sometimes referred to as geo-tagging. Hence, some settings useful for a camera monitoring a scene are the geographic position of the camera, the direction in which the camera is directed, the tilt angle of the camera in relation to a horizontal plane, etc. Other settings useful for a camera having a loudspeaker, e.g. a door station, are sound quality parameters which in many cases depends on the environment in which the loudspeaker is mounted.
Many such settings may be made manually. For instance a person may calculate or get the geographic position of the camera in other ways, may use a compass to get the bearing of the direction in which the camera is capturing images, may use a level in order to approximate the tilting angle of the camera, and then insert these values into the camera. Another example is related to the settings of a loudspeaker where a person will be listening to the loudspeaker playing some sound and making adjustments to settings controlling the loudspeaker until the sound is subjectively good enough.
An alternative way of making settings like these is to provide a device including a display for displaying information helping the camera-based system to make correct settings, a GPS circuit, or any equivalent positioning circuit, for determining the geographic position of the device, an accelerometer for determining tilt or possible roll of the device in relation to the horizontal plane, a compass circuit for determining the direction of the device, a microphone for detecting sounds in the environment, e.g. audio signals sent out from the loudspeaker of the camera system, etc., and make the device display information relating to the settings for the camera. The information for helping the camera-based system make the correct settings may be displayed as a graphical code on the display and the graphical code may include any of the above mentioned information types which are retrievable by the device having the display. This type of system facilitates the process of making settings to the camera system. However, there is a problem with this visual communication of information when it comes to repeatedly updated data, e.g. compass reading, geographic position, tilt angle are all varying when the device with the display is handheld due to hand movement. Moreover when it comes to the sound the device should present information relating to the sound sent by the loudspeaker. This information may be dynamic and ever-changing.
The one problem with communication of repeatedly updated information like this is that there is a risk that the graphical code on the display representing the information to transfer is updated during a frame capturing at the camera. This may be a problem for applications relying on receiving time critical information via the display or for applications where one image frame including corrupt data may be of some kind of disadvantage, e.g., introducing latency in the information transfer by requiring the system interpret the information in the next image frame not being corrupt, problem of never or seldom achieving a non-corrupted transmission as the image registration in the camera and the update of the information transmission display happens to be synchronized or almost synchronized, resulting in the camera capturing images during the update of the information graphic on the display.